• SQL Server数据库连接类SQLHelper.cs


    using System;
    using System.Collections.Generic;
    using System.Text;
    using System.Configuration;
    using System.Data;
    using System.Data.SqlClient;
    using System.Collections;
    using System.Data.Common;
    
    namespace SWDataDB.DAL
    {
        public class SQLHelper
        {
            /// <summary>
            /// The SqlHelper class is intended to encapsulate high performance, 
            /// scalable best practices for common uses of SqlClient.
            /// </summary>
    
    
            //Database connection strings
            public static readonly string SQLConnString = ConfigurationManager.ConnectionStrings["SQLConnString"].ConnectionString;
            //public static readonly string SQLBookConnString = ConfigurationManager.ConnectionStrings["SQLBookConnString"].ConnectionString;
            // Hashtable to store cached parameters
            private static Hashtable parmCache = Hashtable.Synchronized(new Hashtable());
    
            /// <summary>
            /// Execute a SqlCommand (that returns no resultset) against the database specified in the connection string 
            /// using the provided parameters.
            /// </summary>
            /// <remarks>
            /// e.g.:  
            ///  int result = ExecuteNonQuery(connString, CommandType.StoredProcedure, "PublishOrders", new SqlParameter("@prodid", 24));
            /// </remarks>
            /// <param name="connectionString">a valid connection string for a SqlConnection</param>
            /// <param name="commandType">the CommandType (stored procedure, text, etc.)</param>
            /// <param name="commandText">the stored procedure name or T-SQL command</param>
            /// <param name="commandParameters">an array of SqlParamters used to execute the command</param>
            /// <returns>an int representing the number of rows affected by the command</returns>
            public static int ExecuteNonQuery(string connectionString, CommandType cmdType, string cmdText, params SqlParameter[] commandParameters)
            {
    
                SqlCommand cmd = new SqlCommand();
    
                using (SqlConnection conn = new SqlConnection(connectionString))
                {
                    PrepareCommand(cmd, conn, null, cmdType, cmdText, commandParameters);
                    cmd.CommandTimeout = 999;
                    int val = cmd.ExecuteNonQuery();
    
                    cmd.Parameters.Clear();
                    return val;
                }
            }
    
            public static DataSet ExecuteDataSet(string connectionString, CommandType cmdType, string cmdText, params SqlParameter[] commandParameters)
            {
                SqlCommand cmd = new SqlCommand();
                using (SqlConnection connection = new SqlConnection(connectionString))
                {
                    PrepareCommand(cmd, connection, null, cmdType, cmdText, commandParameters);
                    SqlDataAdapter ad = new SqlDataAdapter(cmd);
                    DataSet data = new DataSet();
                    ad.Fill(data);
                    cmd.Parameters.Clear();
                    return data;
                }
            }
    
            /// <summary>
            /// Execute a SqlCommand (that returns no resultset) against an existing database connection 
            /// using the provided parameters.
            /// </summary>
            /// <remarks>
            /// e.g.:  
            ///  int result = ExecuteNonQuery(connString, CommandType.StoredProcedure, "PublishOrders", new SqlParameter("@prodid", 24));
            /// </remarks>
            /// <param name="conn">an existing database connection</param>
            /// <param name="commandType">the CommandType (stored procedure, text, etc.)</param>
            /// <param name="commandText">the stored procedure name or T-SQL command</param>
            /// <param name="commandParameters">an array of SqlParamters used to execute the command</param>
            /// <returns>an int representing the number of rows affected by the command</returns>
            public static int ExecuteNonQuery(SqlConnection connection, CommandType cmdType, string cmdText, params SqlParameter[] commandParameters)
            {
    
                SqlCommand cmd = new SqlCommand();
    
                PrepareCommand(cmd, connection, null, cmdType, cmdText, commandParameters);
                cmd.CommandTimeout = 999;
                int val = cmd.ExecuteNonQuery();
    
                cmd.Parameters.Clear();
                return val;
            }
    
            /// <summary>
            /// Execute a SqlCommand (that returns no resultset) using an existing SQL Transaction 
            /// using the provided parameters.
            /// </summary>
            /// <remarks>
            /// e.g.:  
            ///  int result = ExecuteNonQuery(connString, CommandType.StoredProcedure, "PublishOrders", new SqlParameter("@prodid", 24));
            /// </remarks>
            /// <param name="trans">an existing sql transaction</param>
            /// <param name="commandType">the CommandType (stored procedure, text, etc.)</param>
            /// <param name="commandText">the stored procedure name or T-SQL command</param>
            /// <param name="commandParameters">an array of SqlParamters used to execute the command</param>
            /// <returns>an int representing the number of rows affected by the command</returns>
            public static int ExecuteNonQuery(SqlTransaction trans, CommandType cmdType, string cmdText, params SqlParameter[] commandParameters)
            {
                SqlCommand cmd = new SqlCommand();
                PrepareCommand(cmd, trans.Connection, trans, cmdType, cmdText, commandParameters);
                cmd.CommandTimeout = 999;
                int val = cmd.ExecuteNonQuery();
    
                cmd.Parameters.Clear();
                return val;
            }
            /// <summary>
            /// 获得datatable
            /// </summary>
            /// <param name="connectionString"></param>
            /// <param name="cmdType"></param>
            /// <param name="cmdText"></param>
            /// <param name="commandParameters"></param>
            /// <returns></returns>
            public static DataTable ExecuteReaderDataSet(string connectionString, CommandType cmdType, string cmdText, params SqlParameter[] commandParameters)
            {
                SqlCommand cmd = new SqlCommand();
                SqlConnection conn = new SqlConnection(connectionString);
                DataSet dataset = new DataSet();
                try
                {
                    PrepareCommand(cmd, conn, null, cmdType, cmdText, commandParameters);
                    SqlDataAdapter adapter = new SqlDataAdapter(cmdText, conn);
    
                    adapter.Fill(dataset);
                    cmd.CommandTimeout = 999;
                    cmd.Parameters.Clear();
                }
                catch (Exception e)
                {
                    throw e;
                }
                finally
                {
                    conn.Close();
                }
    
                return dataset.Tables[0];
            }
            /// <summary>
            /// Execute a SqlCommand that returns a resultset against the database specified in the connection string 
            /// using the provided parameters.
            /// </summary>
            /// <remarks>
            /// e.g.:  
            ///  SqlDataReader r = ExecuteReader(connString, CommandType.StoredProcedure, "PublishOrders", new SqlParameter("@prodid", 24));
            /// </remarks>
            /// <param name="connectionString">a valid connection string for a SqlConnection</param>
            /// <param name="commandType">the CommandType (stored procedure, text, etc.)</param>
            /// <param name="commandText">the stored procedure name or T-SQL command</param>
            /// <param name="commandParameters">an array of SqlParamters used to execute the command</param>
            /// <returns>A SqlDataReader containing the results</returns>
            public static SqlDataReader ExecuteReader(string connectionString, CommandType cmdType, string cmdText, params SqlParameter[] commandParameters)
            {
                SqlCommand cmd = new SqlCommand();
                SqlConnection conn = new SqlConnection(connectionString);
    
                // we use a try/catch here because if the method throws an exception we want to 
                // close the connection throw code, because no datareader will exist, hence the 
                // commandBehaviour.CloseConnection will not work
                try
                {
                    PrepareCommand(cmd, conn, null, cmdType, cmdText, commandParameters);
                    cmd.CommandTimeout = 999;
                    SqlDataReader rdr = cmd.ExecuteReader(CommandBehavior.CloseConnection);
    
                    cmd.Parameters.Clear();
                    return rdr;
                }
                catch
                {
                    conn.Close();
                    throw;
                }
            }
    
            /// <summary>
            /// Execute a SqlCommand that returns the first column of the first record against the database specified in the connection string 
            /// using the provided parameters.
            /// </summary>
            /// <remarks>
            /// e.g.:  
            ///  Object obj = ExecuteScalar(connString, CommandType.StoredProcedure, "PublishOrders", new SqlParameter("@prodid", 24));
            /// </remarks>
            /// <param name="connectionString">a valid connection string for a SqlConnection</param>
            /// <param name="commandType">the CommandType (stored procedure, text, etc.)</param>
            /// <param name="commandText">the stored procedure name or T-SQL command</param>
            /// <param name="commandParameters">an array of SqlParamters used to execute the command</param>
            /// <returns>An object that should be converted to the expected type using Convert.To{Type}</returns>
            public static object ExecuteScalar(string connectionString, CommandType cmdType, string cmdText, params SqlParameter[] commandParameters)
            {
                SqlCommand cmd = new SqlCommand();
    
                using (SqlConnection connection = new SqlConnection(connectionString))
                {
                    PrepareCommand(cmd, connection, null, cmdType, cmdText, commandParameters);
                    cmd.CommandTimeout = 999;
                    object val = cmd.ExecuteScalar();
    
                    cmd.Parameters.Clear();
                    return val;
                }
            }
    
    
    
            /// <summary>
            /// Execute a SqlCommand that returns the first column of the first record against an existing database connection 
            /// using the provided parameters.
            /// </summary>
            /// <remarks>
            /// e.g.:  
            ///  Object obj = ExecuteScalar(connString, CommandType.StoredProcedure, "PublishOrders", new SqlParameter("@prodid", 24));
            /// </remarks>
            /// <param name="conn">an existing database connection</param>
            /// <param name="commandType">the CommandType (stored procedure, text, etc.)</param>
            /// <param name="commandText">the stored procedure name or T-SQL command</param>
            /// <param name="commandParameters">an array of SqlParamters used to execute the command</param>
            /// <returns>An object that should be converted to the expected type using Convert.To{Type}</returns>
            public static object ExecuteScalar(SqlConnection connection, CommandType cmdType, string cmdText, params SqlParameter[] commandParameters)
            {
    
                SqlCommand cmd = new SqlCommand();
    
                PrepareCommand(cmd, connection, null, cmdType, cmdText, commandParameters);
                cmd.CommandTimeout = 999;
                object val = cmd.ExecuteScalar();
    
                cmd.Parameters.Clear();
                return val;
            }
    
            /// <summary>
            /// add parameter array to the cache
            /// </summary>
            /// <param name="cacheKey">Key to the parameter cache</param>
            /// <param name="cmdParms">an array of SqlParamters to be cached</param>
            public static void CacheParameters(string cacheKey, params SqlParameter[] commandParameters)
            {
                parmCache[cacheKey] = commandParameters;
            }
    
            /// <summary>
            /// Retrieve cached parameters
            /// </summary>
            /// <param name="cacheKey">key used to lookup parameters</param>
            /// <returns>Cached SqlParamters array</returns>
            public static SqlParameter[] GetCachedParameters(string cacheKey)
            {
                SqlParameter[] cachedParms = (SqlParameter[])parmCache[cacheKey];
    
                if (cachedParms == null)
                    return null;
    
                SqlParameter[] clonedParms = new SqlParameter[cachedParms.Length];
    
                for (int i = 0, j = cachedParms.Length; i < j; i++)
                    clonedParms[i] = (SqlParameter)((ICloneable)cachedParms[i]).Clone();
    
                return clonedParms;
            }
    
            /// <summary>
            /// Prepare a command for execution
            /// </summary>
            /// <param name="cmd">SqlCommand object</param>
            /// <param name="conn">SqlConnection object</param>
            /// <param name="trans">SqlTransaction object</param>
            /// <param name="cmdType">Cmd type e.g. stored procedure or text</param>
            /// <param name="cmdText">Command text, e.g. Select * from Products</param>
            /// <param name="cmdParms">SqlParameters to use in the command</param>
            private static void PrepareCommand(SqlCommand cmd, SqlConnection conn, SqlTransaction trans, CommandType cmdType, string cmdText, SqlParameter[] cmdParms)
            {
    
                if (conn.State != ConnectionState.Open)
                    conn.Open();
    
                cmd.Connection = conn;
                cmd.CommandText = cmdText;
    
                if (trans != null)
                    cmd.Transaction = trans;
    
                cmd.CommandType = cmdType;
    
                if (cmdParms != null)
                {
                    foreach (SqlParameter parm in cmdParms)
                        cmd.Parameters.Add(parm);
                }
            }
    
            /// <summary>
            /// 单表(视图)获取分页SQL语句
            /// </summary>
            /// <param name="tableName">表名或视图名</param>
            /// <param name="key">唯一键</param>
            /// <param name="fields">获取的字段</param>
            /// <param name="condition">查询条件(不包含WHERE)</param>
            /// <param name="collatingSequence">排序规则(不包含ORDER BY)</param>
            /// <param name="pageSize">页大小</param>
            /// <param name="pageIndex">页码(从1开始)</param>
            /// <returns>分页SQL语句</returns>
            public static string GetPagingSQL(
                string tableName,
                string key,
                string fields,
                string condition,
                string collatingSequence,
                long pageSize,
                long pageIndex)
            {
                string whereClause = string.Empty;
                if (!string.IsNullOrEmpty(condition))
                {
                    whereClause = string.Format("WHERE {0}", condition);
                }
    
                if (string.IsNullOrEmpty(collatingSequence))
                {
                    collatingSequence = string.Format("{0} ASC", key);
                }
    
                StringBuilder sbSql = new StringBuilder();
    
                sbSql.AppendFormat("SELECT  {0} ", PrependTableName(tableName, fields, ','));
                sbSql.AppendFormat("FROM    ( SELECT TOP {0} ", pageSize * pageIndex);
                sbSql.AppendFormat("                    [_RowNum_] = ROW_NUMBER() OVER ( ORDER BY {0} ), ", collatingSequence);
                sbSql.AppendFormat("                    {0} ", key);
                sbSql.AppendFormat("          FROM      {0} ", tableName);
                sbSql.AppendFormat("          {0} ", whereClause);
                sbSql.AppendFormat("        ) AS [_TempTable_] ");
                sbSql.AppendFormat("        INNER JOIN {0} ON [_TempTable_].{1} = {0}.{1} ", tableName, key);
                sbSql.AppendFormat("WHERE   [_TempTable_].[_RowNum_] > {0} ", pageSize * (pageIndex - 1));
                sbSql.AppendFormat("ORDER BY [_TempTable_].[_RowNum_] ASC ");
    
                return sbSql.ToString();
            }
    
            /// <summary>
            /// 给字段添加表名前缀
            /// </summary>
            /// <param name="tableName">表名</param>
            /// <param name="fields">字段</param>
            /// <param name="separator">标识字段间的分隔符</param>
            /// <returns></returns>
            public static string PrependTableName(string tableName, string fields, char separator)
            {
                StringBuilder sbFields = new StringBuilder();
    
                string[] fieldArr = fields.Trim(separator).Split(separator);
                foreach (string str in fieldArr)
                {
                    sbFields.AppendFormat("{0}.{1}{2}", tableName, str.Trim(), separator);
                }
    
                return sbFields.ToString().TrimEnd(separator);
            }
    
            /*
            nzperfect [no_mIss] 高效通用分页存储过程(双向检索) 2007.5.7  QQ:34813284
            敬告:适用于单一主键或存在唯一值列的表或视图
            ps:Sql语句为8000字节,调用时请注意传入参数及sql总长度不要超过指定范围
             * 
    
            @TableName VARCHAR(200),     --表名
            @FieldList VARCHAR(2000),    --显示列名,如果是全部字段则为*
            @PrimaryKey VARCHAR(100),    --单一主键或唯一值键
            @Where VARCHAR(2000),        --查询条件 不含'where'字符,如id>10 and len(userid)>9
            @Order VARCHAR(1000),        --排序 不含'order by'字符,如id asc,userid desc,必须指定asc或desc                                 
                                         --注意当@SortType=3时生效,记住一定要在最后加上主键,否则会让你比较郁闷
            @SortType INT,               --排序规则 1:正序asc 2:倒序desc 3:多列排序方法
            @RecorderCount INT,          --记录总数 0:会返回总记录
            @PageSize INT,               --每页输出的记录数
            @PageIndex INT,              --当前页数
            @TotalCount INT OUTPUT,      --记返回总记录
            @TotalPageCount INT OUTPUT   --返回总页数
            */
            /// <summary>
            /// 调用存储过程 分页查询
            /// </summary>
            /// <param name="TableName">表名</param>
            /// <param name="FieldList">显示列名,如果是全部字段则为*</param>
            /// <param name="PrimaryKey">单一主键或唯一值键</param>
            /// <param name="Where">查询条件 不含'where'字符,如id>10 and len(userid)>9</param>
            /// <param name="Order">排序 不含'order by'字符,如id asc,userid desc,必须指定asc或desc</param>
            /// <param name="SortType">排序规则</param>
            /// <param name="RecorderCount">记录总数</param>
            /// <param name="PageSize">每页输出的记录数</param>
            /// <param name="PageIndex">当前页数</param>
            /// <param name="TotalCount">记返回总记录</param>
            /// <param name="TotalPageCount">返回总页数</param>
            /// <returns></returns>
            public static DataSet P_viewPage(string TableName, string FieldList, string PrimaryKey, string Where, string Order,
                                    int SortType, int RecorderCount, int PageSize, int PageIndex, out int TotalCount, out int TotalPageCount)
            {
                string strSql = "P_viewPage";
                int totalCount = 0;
                int totalPageCount = 0;
    
                SqlParameter[] arrSqlPara = new SqlParameter[]
               {
    
                   new SqlParameter("@TableName",TableName),
                   new SqlParameter("@FieldList",FieldList),
                   new SqlParameter("@PrimaryKey",PrimaryKey),
                   new SqlParameter("@Where",Where),
                   new SqlParameter("@Order",Order),
                   new SqlParameter("@SortType",SortType),
                   new SqlParameter("@RecorderCount",RecorderCount),
                   new SqlParameter("@PageSize",PageSize),
                   new SqlParameter("@PageIndex",PageIndex),
                   new SqlParameter("@TotalCount",totalCount),
                   new SqlParameter("@TotalPageCount",totalPageCount),
    
               };
    
                arrSqlPara[9].Direction = ParameterDirection.Output;
                arrSqlPara[10].Direction = ParameterDirection.Output;
    
               DataSet ds = SQLHelper.ExecuteDataSet(SQLHelper.SQLConnString, CommandType.StoredProcedure, strSql, arrSqlPara);
    
               TotalCount = int.Parse(arrSqlPara[9].Value.ToString());
               TotalPageCount = int.Parse(arrSqlPara[10].Value.ToString());
    
               return ds;
    
                //return SQLHelper.ExecuteNonQuery(SQLHelper.SQLConnString, CommandType.StoredProcedure, strSql, arrSqlPara);
            }
    
        }
    }
    
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  • 原文地址:https://www.cnblogs.com/hyqing/p/3704049.html
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